Burner assembly for hydrocarbon fuel



y 1963 J. K. SIDDLE ETAL 3,099,436

BURNER ASSEMBLY FOR HYDROCARBON FUEL Filed Feb. 4, 1960 I 2 Sheets-Sheet 1 co/z.

INVENTORS". JOHN K. SIDDLE y HAROLD L. MlLLER AT TORN EV July 30, 1963 J. K. SIDDLE EI'AL BURNER ASSEMBLY FOR HYDROCARBON FUEL Z Sheets-Sheet 2 Filed Feb. 4, 1960 uvmvrons. JOHN K. SIDDLE BY HAROLD L. MILLER ATTORNEY United States Patent Ofiice 3,699,436 Patented July 30, 1963 3,099,466 BURNER AEMBLY Ftlli HYDRQCAREUN FUEL John K. Siddle and Harold L. Miller, (lolurnbus, ()hio, assignors to Midland-Ross Corporation, Qleveland, Ohio, a corporation of Ohio Filed Feb. 4, 1960, er. No. 6,665 3 Claims. (Cl. 263-4 3) This invent-ion relates to a burner assembly for burning hydrocarbon fuel and providing heat in the form of hot combustion products gases and mixtures of combustion products gases and air for carrying heat to a usable location.

The vaporization of gasoline and combustion of the vapors as a fuel after they have been passed through a burner orifice is difficult because, unless the burning is at a closely controlled temperature with closely controlled mixtures of air and fuel, carbon is formed during the combustion and is deposited as soot within the combustion chamber and on the burner parts and frequently extinguishes the flames. A second problem also exists in the combustion of gasoline in a gas generating type burner due to the presence of gum and other heavy materials in the gasoline which are deposited out during vaporization of the liquid to a gas onto the surfaces in the vaporizing chamber and the fuel jets. Either of these deposits renders the burner ineflicient and may cause the flame to be extinguished after relatively short peniods of heating.

It has been discovered that deposits as a result of vaporization can be eliminated by close temperature control of the burner vaporizing chamber, for example, by the careful control of combustion air temperature.

It is, therefore, the principal object of this invention to provide a burner assembly comprising a vaporization chamber for the combustion of a liquid hydrocarbon fuel in which the temperature at which the fuel is vaporized in the vaporization chamber is closely controlled. It is a further object of the invention to control the temperature of the fuel vaporization chamber by subjecting it to the thermal action of a supply of air for combustion comprising streams of cold air and preheated air. It is a further object of the invention to provide means responsive to the temperature of the vaporization chamber to vary the relative rates of flow of the streams of cold air and preheated air to maintain the temperature of the vaporization chamber at a substantially constant value.

It is another object of the instant invention to provide a simple, portable, lightweight burner for gasoline to provide hot gases for the heating of equipment under field conditions, as, for example, for the heating of military equipment at locations remote from permanent installations.

More specifically, it is an object of the instant invention to provide a lightweight portable burner assembly for burning gasoline, for example, aviation gasoline, to provide hot gases for maintaining operative temperatures of equipment such as a portable fire extinguisher kit.

These and other more specific objects and advantages of the invention will be better understood from the specification which follows and from the drawings. in which:

FIGURE 1 is a fragmentary view in front elevation, with parts broken away, of a burner assembly embodying the invention;

FIG. 2 is a fragmentary view in cross section and on an enlarged scale, taken along the line 2--2 of FIG. 1;

FIG. 3 is a fragmentary side view taken from the position indicated by the line 33 of FIG. 1, with parts broken away; and

FIG. 4 is a fragmentary View similar in part to FIG.

3, but showing portions of the mechanism at a different operating position.

A burner assembly embodying the invention has a main housing 10 comprising a bottom wall 11, side walls 12 and 13, a front wall 14 and a back wall 15. The main portion of the housing 19 in the embodiment illustrated in the drawings is generally rectilinear. At the upper end of the housing it), the front wall 14 has a rearwardly directed, inclined section 16, and the side walls 12 and 13, inclined section 16 and rear wall 15 are capped by a cupola 17 over which a vent pipe 18 is positioned. The housing 10 has a main side door 1'? supponted by hinge plates 21 which are welded or otherwise secured to the side wall 12.

The burner assembly embodying the invention has a substantially conventional burner unit generally indicated at 21, with a stack 22 extending upwardly from the unit 21 and opening within the confines of the housing 10. The burner unit 21 is supported in the housing 10 on a hollow stand 23 with a packing gland 24 securing the stand 23 in place on the bottom wall 1 1 and with control elements 25 extending downwardly through the gland 24 and into the interior of a hollow base 26. Adjustable elements 25 function to determine the rate of flow of fuel, specifically gasoline, into the burner unit 21.

A burner assembly embodying the invention has an air inlet duct generally indicated at 27, for the purpose of supplying and heating air from outside the housing 10* to the burner unit 21. The hot air duct 27 in the embodiment shown has two inlet openings 28 and 29 at the sides and near the top of the inclined section 16 of the front wall 14. The hot air duct 27 extends laterally across and immediately behind the wall section 16 and is located above the end of the combustion stack 22. The air duct 27 narrows as it extends downwardly along the wall section 16 and the front wall 14 and has an open lower end 30. Air supplied by the duct 27 is preheated as it passes through the upper portion of the duct 27 by reason of the exposure thereof to the hot gases flowing out of the combustion stack 22. The air which is preheated in duct 27 is admitted to housing 10 through open lower end 30 of duct 27. To effect proper control of the temperature of the vaporization chamber 21a of burner 21 it is necessary that the stream of preheated air from duct 27 be caused to flow by vaporization chamber 21a in heat transfer relationship therewith. This is accom plished by locating the open lower end 30 of duct 27 adjacent burner unit 21 and sufliciently far from vent pipe 18 so that the preheated air from duct 27 will enter housing 10 at a point that is at least as far upstream of vent pipe 18 as is vaporization chamber 21a of burner unit 21.

The door 32 is mounted by hinge plates 33 which are welded or otherwise secured on the front wall 14 of the housing 119. The door 32 has a counterweight 34 which is mounted upon an angular bracket 35 and which tends to cause the door 32 to swing to the closed position illustrated in FIG. 3.

At the lower end of the hot air duct 27 is a cold air inlet port '31 which functions to provide cold air to housing 10. It is, of course, also necessary that the cold air from inlet port 31 be caused to flow by vaporization chamber 21a in heat transfer relationship therewith to properly control the temperature of vaporization chamber 21a. Accordingly, cold air inlet port 31 is also located sufficiently far from vent pipe 18 that the cold air will be caused to enter housing 10 at a point that is at least as far upstream of vent pipe 18 as is vaporization chamber 21a of burner unit 2 1. The amount of cold air entering the burner housing is controlled by the position of a door 32 for the port 31. The temperature of the air inside the burner housing is controlled by the relative amounts of cold and hot air drawn into the burner housing. For example, if the vaporization chamber of the burner (designated 21a), or the body of the burner unit 21, becomes hotter-than the ideal temperature for-the fuel being used, the cold air door 32 is opened to increase the rate of flow of cold air through housing 16 past vaporization chamber 21a, relative to the rate of flow of preheated air, thereby to exert a cooling effect on vaporization chamber 21a.

Movement of the door 32 and, in the embodiment illustrated in the drawings, opening of the cold air inlet port 31 are both accomplished by a temperature responsive mechanism comprising an actuating arm 36. The actuating arm 36 has an offset finger 37 in line to engage with the cross portion of a bracket 38 on the door 32 and to swing it in a clockwise direction (FIGS. 3 and 4) as the arm 36 is swung in response to temperature changes in the burner unit 21. The cooler air will reduce the temperature of the vaporization chamber of the burner back to the desired ideal temperature. The arm 36 also has a cross member 39 which extends along the back of the burner unit 21 and functions as a stop.

The arm 36 is keyed or set on the end of a stub shaft 40 which extends horizontally and is journaled for rotation in a plate 41 secured to the outer face of a retainer block 42. The retainer block 42 is rigidly mounted on the side of the burner unit 211. The retainer block 42 has a circular recess 43 coaxial with its bore for the shaft 40, and serving to accommodate a thermostat coil 44. The inner end of the thermostat coil 44 extends through a slot 45 in the shaft 49* and the outer end of the thermostat coil 44 is hooked in a radial slot 56 in the block 42.

When the vaporization chamber of the burner becomes cooler than the ideal temperature, the cold air inlet port door closes via movement controlled by the thermostat coil 44, arm 36, and bracket 38. Closing the cold air inlet door 32 decreases the rate of flow of cold air through housing 10 past vaporization chamber 21a, relative to the rate of flow of preheated air, thereby to exert a heating effect on vaporization chamber 21:: to restore its temperature to the desired ideal value. The unit is designed so that the cold air inlet port door 32 will normally be open slightly while operating under the coldest conditions so there will be some control left for warming the air further in the event the vaporization chambers should become colder than the ideal temperature.

It has been found that the burner assembly embodying the invention disclosed in the drawings, with the indicated mechanism is capable of limiting deviations from a predetermined temperature of the burner unit 21 to about F., and that with such close temperature control fouling from gum and other deposits is reduced to such an extent that the burner is capable of operation for long periods of time without attention. It will be appreciated that means other than the door 32 for controlling the proportions of heated and cold air can also be used to control temperature as discussed. For example, a damper can be used in the heated air inlet in lieu thereof or in addition thereto, or the cold air inlet can be eliminated so that all combustion air is heated, and the temperature can be controlled by a damper which is actuated to reduce the rate of flow in response to a lowered temperature, and to increase the rate in response to an increased temperature. In such case, means must be provided to prevent the complete blocking of the air inlet when the vaporization chamber is cold. Such means can comprise a stop which prevents complete shuttling of the damper, or an orifice through the damper for supplying combustion air even when the damper is closed. Both cold air and heated air inlets and means for proportioning the flow through at least one of the two are preferred, because variations in the rate at which combustion air is supplied are then minimized.

We claim:

1. A burner assembly for liquid hydrocarbon fuel comprising, in combination, a housing, a hot gas vent means leading from said housing, a burner unit having a fuel vaporization chamber and located in said housing for discharging products of combustion into said housing for how therein and through said vent means, means for introducing liquid hydrocarbon fuel to said vaporization chamber for vaporization therein, an air inlet for said burner unit disposed in heat transfer relationship to the products of combustion flowing in said housing for supplying preheated air to said burner unit at a point that is at least as far upstream of the hot gas vent means as the vaporization chamber, a variable cold air inlet port means associated with said housing for supplying cold air to said burner unit at a point that is at least as far upstream of the hot gas vent means as the vaporization chamber, means responsive to the tempenature in said vaporization chamber, and means actuated by said temperature responsive means for varying the opening and closing of said cold air inlet port means for controlling the quantity of cold air admitted therethrough for said burner unit to maintain the temperature of the fuel vaporization chamber at a substantially constant value.

2. A burner assembly for liquid hydrocarbon fuel comprising, in combination, a housing, a hot gas vent means leading from an upper part of said housing, a burner unit having a fuel vaporization chamber and located in said housing for discharging products of combustion into said housing for flow therefrom through vent means, means for introducing liquid hydrocarbon fuel to said vaporization chamber for vaporization therein, an air inlet duct lea-ding into and through at least a part of said housing and terminating near said burner unit for supplying pre-heated air to said housing at a point that is at least as far upstream of the hot gas vent means as the vaporization chamber, a cold air inlet port in said housing near said burner unit for supplying cold air to said housing at a point that is at least as far upstream of the hot gas vent means as the vaporization chamber, a movable door for said port, means responsive to the temperature in said vaporization chamber and means actuated by said tem perature responsive means for varying said door for said cold air inlet port between open and closed positions for controlling the quantity of air flowing through said cold air inlet port to maintain the temperature of the fuel vaporization chamber at a substantially constant value. 3. A burner assembly for liquid hydrocarbon fuel comprising, in combination, a housing, a hot gas vent means leading from said housing, a burner unit having a fuel vaporization chamber and located in said housing for discharging products. of combustion into said housing for flow therein and through said vent means, means for introducing liquid hydrocarbon fuel to said vaporization chamber for vaporization therein, an air inlet for said burner unit disposed in heat transfer relationship to the products 'of combustion flowing in said housing for supplying preheated air to said burner unit at a point that is at least as far upstream of the hot gas vent means as the vaporization chamber, a cold air inlet port means. associated with said housing for supplying cold air to said burner unit at a point that is at least as far upstream of the hot gas vent means as the vaporization chamber, means responsive to the temperature in said vaporization chamber, and means actuated by said temperature responsive means for varying the relative proportion of air admitted through said inlet and said port means for said burner unit to maintain the temperature of the fuel vaporization chamber at a substantially constant value.

References Cited in the file of this patent UNITED STATES PATENTS 1,972,836 Te Pas Sept. 4, 1934 2,137,469 VJillson NOV. 22, 1938 2,174,663 Keller Oct. 3, 1939 2,287,346 Fishel June 23, 1942 2,859,807 Newman et al Nov. 11, 1958 

3. A BURNER ASSEMBLY FOR LIQUID HYDROCARBON FUEL COMPRISNG, IN COMBINATION, A HOUSING, A HOT GAS VENT MEANS LEADING FROM SAID HOUSING, A BURNER UNTI HAVING A FUEL VAPORIZATION CHAMBER AND LOCATED IN SAID HOUSING FOR DISCHARGING PRODUCTS OF COMBUSTION INTO SAID HOUSING FOR FLOW THEREIN AND THROUGH SAID VENT MEANS, MEANS FOR INTRODUCING LIQUID HYDROCARBON FUEL TO SAID VAPORIZATION CHAMBER FOR VAPORIZATION THEREIN, AN AIR INLET FOR SAID BURNER UNIT DISPOSED IN HEAT TRANSFER RELATIONSHIP TO THE PRODUCTS OF COMBUSTION FLOWING IN SAID HOUSING FOR SUPPLYING PREHEATED AIR TO SAID BURNER UNIT AT A POINT THAT IS AT LEAST AS FAR UPSTREAM OF THE HOT GAS VENT MEANS AS THE VAPORIZATION CHAMBER, A COLD AIR INLET PORT MEANS ASSOCIATED WITH A POINT THAT IS AT LEAST AS FAR UPSTREAM OF THE HOT GAS VENT MEANS AS THE VAPORIZATION CHAMBER, MEANS RESPONSIVE TO THE TEMPERATURE IN SAID VAPORIZATION CHAMBER, AND MEANS SAID HOUSING FOR SUPPLYING COLD AIR TO SAID BURNER UNIT AT 